<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			body,html{
				height: 100%;
			}
			img{
				/* width:50vw; /* 相对于屏幕的50% */ 
				height:50%;
			}
		</style>
	</head>
	<body>
		<img src="img/pzhu.jpg">
	</body>
</html>
